This invention relates to feed tube protectors for food processors, and more particularly to such a protector in which actuator means are provided on both the cover and feed tube protector such that both the feed tube protector and the cover must be properly installed together by the user in order to enable the operation of the food processor to occur for protecting both the user and the processor.
Food processors of the type to which the present invention is applicable have a working bowl with a motor-driven member projecting into the bowl with which various selected rotary food processing tools can be engaged to be driven for performing various food processing operations in accordance with the desires of the user. A detatchable cover is secured over the top of the bowl during use and the cover includes a feed tube having a mouth which opens downwardly through the cover into the top of the bowl. Food items to be processed are placed in the feed tube and then manually pushed down through the feed tube into the bowl by means of a food pusher which is adapted to slide down in the manner of a plunger through the feed tube.
A bowl cover safety feature is conventionally provided which requires that the cover be firmly locked on the bowl in normal operating position before the motor of the food processor will start. The cover which locks rotationally on the bowl is provided with a projection or actuator which causes the actuation of control means such as a switch carried by the housing only when the cover is properly locked in normal operating position on the bowl. In this arrangement, the motor cannot be energized before the cover is properly positioned on the bowl, but the size of the feed tube is restricted in terms of shape, cross-section and height to prevent an adult hand from being inadvertently inserted sufficiently far down in the feed tube as to come into contact with the rotating blade located in the upper portion of the working bowl.
In my U.S. Pat. No. 4,226,373 a feed tube protector is provided having an outer sleeve which carries an actuator for making the machine operative only when this sleeve is properly positioned over the feed tube. The sleeve also carries a captivated, movable food pusher which is mounted for movement within the sleeve and within the passageway in the feed tube. Accordingly, the feed tube can be expanded to any cross-sectional area and shape which is practicable, and when the outer sleeve of the feed tube protector is properly positioned on the feed tube, the actuator extending therefrom is operatively associated with a control means in the food processor to permit operation of the motor drive only when this expanded feed tube protector is properly nested around and positioned on the feed tube of the cover. If the cover were omitted, the actuator of the expanded feed tube protector might be engaged with the control means of the food processor, thereby enabling the processor to be operated without its cover, a very unlikely event, but nevertheless undesirable even though a remote situation.